Pls advise me when is the off peak hour to be at the Gongbei Port for crossing to Guangzhou?

You may cross the border in the early morning before 9:00, or there will be crazy long queue. Then walk to Gongbei Bus Station to take a long-distance bus to Guangzhou. Get off at the Provincial Bus Station. Then walk to Guangzhou Railway Station to take subway line 5 to Taojin Station. Leave from exit A and you can see the hotel within 150yd.